OBJECTIVE: To compare individuals with and without hyperhidrosis in terms of the intensity of palmar and plantar sweating. METHODS: We selected 50 patients clinically diagnosed with palmoplantar hyperhidrosis and 25 normal individuals as controls. We quantified sweating using a portable noninvasive electronic device that has relative humidity and temperature sensors to measure transepidermal water loss. All of the individuals had a body mass index of 20-25 kg/cm2. Subjects remained at rest for 20-30 min before the measurements in order to reduce external interference. The measurements were carried out in a climate-controlled environment (21-24ºC). Measurements were carried out on the hypothenar region on both hands and on the medial plantar region on both feet. RESULTS: In the palmoplantar hyperhidrosis group, the mean transepidermal water loss on the hands and feet was 133.6 ± 51.0 g/m2/h and 71.8 ± 40.3 g/m2/h, respectively, compared with 37.9 ± 18.4 g/m2/h and 27.6 ± 14.3 g/m2/h, respectively, in the control group. The differences between the groups were statistically significant (p < 0.001 for hands and feet). CONCLUSIONS: This method proved to be an accurate and reliable tool to quantify palmar and plantar sweating when performed by a trained and qualified professional.